just because he knew all the techs in konoha doesnt mean anything about bloodline limits. a weak version of him barely stood up to orochimaru who was a push over for the other characters you mentioned. what could sarutobi and enma in their primes do against pain attacking the village? probably just die in his wake. also its common knowledge that minato was the best ninja ever in konoha. i could be wrong but i think even sarutobi says it at some point

Have you even checked up on Sarutobi? He didn't just know every Konoha jutsu, he possibly knew more. Not only that he was considered the God of Shinobi, he was also said to be the strongest Hokage that Konoha has ever had, including Minato and strongest of all the five kages of his time.
A weak version barely stood up to Orochimaru? Dude, Orochimaru was in perfect condition and summoned two other Hokage, each considered quite powerful and what about him? He was a 70 year old man who probably hadn't fought since Minato got the Hokage job, if not sooner. My grandpa is around that age, he takes long walks every day and yet feels tired just walking for a bit, imagine fighting 3 powerful guys.
He didn't beat Orochimaru but still managed to take away his arms...after using Shadow clone twice, meaning his energy was even cut by 2/3 after a while of fighting.
And don't underestimate Orochimaru...people have tended to underestimate Orochimaru because he was beaten by Sasuke...but don't forget he was bed-ridden by then and even then Sasuke didn't kill him, only Itachi's Susanoo managed to finally take him out. Orochimaru couldn't use his arms and was weakened yet he still held out against both Jiraya (though drugged) and Tsunade...
What about the 1st and the 2nd Hokage, also in the fight? One managed to beat Madara and the other was considered the best water user ever.
Also...Ninjas don't need bloodline limits to be powerful.